1. Field
Example embodiments relate to an uplink scheduling method using one bit per user feedback.
2. Description of the Related Art
In a wireless multiuser system wherein a plurality of users have independent fading channels, it is highly probable that one of the users always has a good channel condition. Hence, multiuser diversity may be utilized to enhance the sum-rate capacity of the system. However, to acquire multiuser diversity gain, channel gain has to be estimated for all the users and the user terminals have to transmit feedback information to the base station. Accordingly, a large quantity of feedback information is required.
The one-bit feedback scheme has been proposed to reduce feedback load for utilization of multiuser diversity. Based on the user's one-bit information, it is informed to the base station whether the user's channel gain is greater than the threshold. This method can achieve multiuser diversity gain in terms of the sum-rate capacity if a threshold is carefully chosen and the number of users is large. However, it deals only with a network in which all users have identical channel statistics. In real environment, however, the channel statistics are not identical since users which are closer to the base station have better average channel gains.
Accordingly, the one-bit feedback scheme can be applied only to the ideal environment where all the users have identical channel statistics.